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A Network Model of Membrane Polarization to Simulate the Induced Polarization Response of Sandstone Samples
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 23rd European Meeting of Environmental and Engineering Geophysics, Sep 2017, Volume 2017, p.1 - 5
Abstract
The hydraulic conductivity of sediments is an essential parameter for many applications, and thus its estimation from induced polarization (IP) measurements is an important aim of current research. For this purpose, a comprehensive understanding of the processes at the pore scale is necessary. We suggest a membrane polarization model based on a sequence of two cylinders with different size. To account for the complexity of real rock, we combine many impedances calculated for such a 2-cylinder model into a network. We define global network parameters, which we tune in such a way that macroscopic properties, such as specific internal surface area, porosity, and fractal dimension, match those measured for real sandstone samples. Using remaining degrees of freedom of the network we are able to simulate the IP parameters, namely maximum phase shift and relaxation time, of the measured samples. Matching the IP parameters gets more difficult if we also try to constrain the network by data from µ-CT measurements. We conclude that the impedance network has a great potential to connect bulk electrical properties with microscopic geometry.